Objective: Candidiasis caused by Candida species has been reported worldwide in humans. In a study conducted in 1998 with samples of vaginal discharges of outpatients and prostitutes in Istanbul, a prevelance of candidiasis of 30.3% and 11.4%, respectively was found. The aim of this study was to determine the changes in the rate of candidiasis in prostitutes and outpatients during the past ten years. Method: Vaginal discharge samples of 207 patients with suspected trichomoniasis vaginitis were examined. The samples were obtained from 93 prostitutes admitted to the Hospital of Skin and Venereal Diseases and from 114 outpatients admitted to Istanbul Medical Faculty, Department of Obstetrics and Gynecology Outpatient Clinic. Smears prepared from the samples were examined under a microscope by Gram staining. Additionally, Candida culture tests were performed by inoculating a fluid and a solid Sabouraud medium. Results: Candida was identified in 31 (14.9%) of the 207 samples of vaginal discharges examined, while yeast cells were detected in 25 of them (80.7%) by Gram staining. Twenty-one (67.7%) of the Candida identified, belonged to the species Candida albicans, five (16.1%) were Candida krusei, two (6.5%) Candida tropicalis and three (9.7%) Candida spp.. Candida was reported in 10 (10.8%) of the 93 prostitutes, and in 21 (18.4%) of outpatients. Conclusion: Second to bacterial infections of vagina, vaginal candididiasis is the most common disease in women of all ages. Even though a reduction in the prevalance of candidiasis was observed in outpatients as compared to ten years ago, this was not the case in prostitutes. We think that this kind of epidemiological studies are important in determining the level of hygienic conditions in different social groups.